Insulating and anti-induction tube for electric conductors



(No Model.) I 2 ShetQ-Sheet 1. F. B. RAE.

INSULATING AND ANTI-INDUCTION TUBE FOR ELECTRIC QONDUCTORS.

No. 325.630. Patented Sept. 1, 1885.

N. PETERS, Phoeo-Lilha m lmr. Washington, D. c

2 Sheets-Sheet 2.

(No Model.)

F. B. RAE.

INSULATING AND ANTI-INDUCTION TUBE FOR ELEGTRIG GONDUGTORS.

Patented Sept. 1, 1885.

Wzliflesss v Iva/@77 0 N. PETERS. Pnaw-Lnhn n hor. wnhm mn. D. C.

UNITED STATES PATENT OFFICE.

FRANK B. RAE, OF NEWVARK, NEXV JERSEY.

INSULATING AND ANTI-INDUCTION TUBE FOR ELECTRIC CONDUCTORS.

SPECIFICATION forming part of Letters Patent No. 325,630, dated September 1, 1885.

Application filed November 13, 1884.

T0 aZZ whom it may concern.-

Be it known that I, FRANK B. RAE, a citizen of the United States, and a resident of Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Combined Insulating and Anti-Induction Tubes for Electric Conductors, of which the following is a specification.

My invention relates to means for insulating electric conductors and protecting the same from the disturbing effects of electric induction.

My invention consists of a new article of manufacture, comprising a stiff or rigid paper tube adapted to permit the electric conductor to be slipped into place after the tube is laid, and having incorporated between its inner and outer walls an anti induction sheath, the whole forming a rigid envelope adapted to be transported and to be laid in any desired position without injury to the anti-induction envelope.

The advantages arising from my invention will be readily understood by those skilled in the art from the annexed description and drawings.

My invention Consists, further, in certain details of construction, that will be more specifically stated in the claims.

Referring to the accompanying drawings, Figure l is a perspective View of a tube constructed in accordance with my invention. Fig. 2 is a modified form of the same. Figs. 3, 4., 5, and 6 show other forms of the invention. Figs. 7 and 8 show in side View and crosssection a number of the tubes in an underground conduit. Figs. 9 and 10 show the manner in which connection is made between the anti-induction sheaths of contiguous sections.

A indicates a paper tube made of compressed paper-pul p, formed upon a suitable mandrel or otherwise constructed, and having abore of sufficient size to permit the conductor B to he slipped into it after laying the tube. In Fig. 2 the tube is formed with a double aperture or bore. The tube is compressed or treated in the process of manufacture so as to be hard and firm and form a rigid structure capable of retaining its shape and of being readily transported.

(No model.)

0 indicates the induction-sheath, consisting of a wire or sheet of copper or other metal embedded between the inner and outer walls of the paper tube, so as to be protected thereby and to aid in giving stiffness to the tube. The tube being rigid, no injury to the antiduct-ion shield can occur from the bending of the tube. In Fig. 1 the shield is a copper wire, while in Fig. 3 it is made of a spiral of sheet metal. The shield is incorporated with the tube by being embedded in the paperpulp during the process of manufacture. \Vhen the tube is laid, the wire or strip acts as an anti'induction shield when connected in the usual and well-known way either to earth or as a return-conductor for the conductor B.

In Fig. 3 the induction-shield is made by electroplating upon a form of paper, to which is afterward applied the outer paper envelope formed of pulp, compressed thereon or otherwise applied, so that a complete rigid paper tube will result, in which the inductionshield is embedded between the inner and outer walls. The electroplated sheet or film is applied by coating the paper surface with plumbago or carbon or other suitable conducting substance, and then electroplating with copper or other suitable metal. I prefer to apply the plumbago before the paperpulp is fully hardened. The electroplated film might be applied to the form of tube shown in Figs. 5 and 6.

In Fig. 5 the paper tube is shown as con structed by winding several layers of paper tightly and compressing or solidifying them upon a proper mandrel or former. The induction-shield is a spiral of metal applied between the layers at the proper stage of manufacture.

In Fig. 6 the shield is a sheet-metal tube or sheath interposed between the inner and outer walls of the paper. In each instance the tube is sufficiently rigid so as not to bend or give way to the injury of the induction-shield. The shield itself assists in giving the desired rigidity to the paper tube to permit the same to be handled and laid without breakage or compression.

Figs. 7 and 8 show a series of tubes coir tained in a porcelain or other pipe adapted to support and protect the tubes when buried. Such pipe might, howeyer, be dispensed with and the tubes buried in a trench or otherwise laid or supported.

In Figs. 9 and 10 I have shown two adjoining sections of paper tube united and their induction-shields brought into firm contact by means of the coupling-nuts D, applied to the exterior of the tube. Connection is made by the portions exposed at the end of the sections and abutting directly against one another. \Vhen the shield consists of a spiral wire, as indicated in Fig. 10, the end of the spiral may be brought to a ring, on, let into the end of the tube, as indicated. The rings in the abutting ends of the sections abut against one another and complete the connection.

By my invention not only is good insulation obtained, but the evils of induction are cheaply and etliciently overcome, while at the same time the danger of displacement of the iuduction'sheath is largely avoided.

I am aware that it is not new to use pipes of paper as insulating covers or sheaths for electric conductors, as such are described in the patent to IV. and T. G. McMahon, No. 273,869.

I am also aware that induetion-shields have been applied to the insulating-eovering of wires when the cover is attached to and made virtually a part of the wire; but in such cases the complete wire and cover therefor are ordinarily flexible, and the sheath is liable to injury by bending. In my invention the tube and sheath mutually contribute to the still ness of the separate portable tube and aid in preserving the form of the same. This is ob viously an especially desirable feature in the ease of insulating paper tubes that are to be transported and laid, and are required to maintain their form, so that the conducting wire may be slipped in and out.

\Vhat I claim as my invention is- 1. As a new article of manufacture, a rigid insulating tube of paper, having a bore adapted to permit an electric conductor to be slipped into place therein after the tube is laid, said tube having an anti-induction sheath incorporated therewith between its inner and outer walls.

2. As a new article of manufacture, an insulating paper tube having a bore adapted to receive an electric conductor after the tube has been laid, and provided with an anti induction sheath consisting of a film of metal electroplated in the body of the tube between its inner and outer walls.

As a new article of manufacture, a rigid insulating-tube for electric conductors formed of plastic material and providedwith a bore, into which the conductor may be slipped after the tube is laid, said tube being provided with an anti-induction conductorincorporated in the body thereof between its inner and outer walls, so that said conductor is protected from injury, while at the same time contributing to give the complete tube the rigidity desirable for permitting the same to be transported and to be laid without injury.

c. As a new article of manufacture, a paper tube having a bore adapted to receive an electric conductor, as described, and formed of paper-pulp having incorporated with it between its inner and outer suiices an anti induction sheath or conductor.

5. The combination, with the two sections of insulating-tube, each having an anti-induction conductor terminating in the abutting faces of the sections, of a coupling applied to the sections, so as to hold the same together, while-at the same time assisting in making good electric connection between the two antiinduction conductors by forcing their ends together:

Signed at New York, in the county of New York and State of New York, this 29th day of October, A. D. 188st.

FRANK B. RAE.

Vitnesses:

Tnos. Tooiunv, \VM. H. BLAIN. 

